Prison policy mandates that guards conduct cell checks on special inmates such as Castro at least every half-hour.

The report also found that there were falsified log entries during that six-hour time period.

Castro, 53, was sentenced to life plus 1,000 years in August for abducting, raping, and beating three women he kept imprisoned in his Cleveland-area home for nearly 10 years.

One of the women was able to escape in May after neighbors heard her screams and called 911. Police responded and removed the other victims from Castro's home.

The Department of Rehabilitation and Correction report also revealed new details surrounding Castro's suicide. For example, in his cell he had a Bible open to the book of John, as well as pictures of his family arranged in a poster-board fashion.

However, the report did claim that "there appears to be no known, substantiated motivation for the self-inflicted death."